cygnusx1 Posted May 28, 2008 Share Posted May 28, 2008 I might already know the answer to this but I will ask your opinions. Yes, I have tha AZC racing brakes all around but when I hit the brakes really hard, the car kind of tends to go right. It doesn't pull the steering wheel much but the car tends to want to go towards the right shoulder a little. If I let go of the steering wheel and brake hard, the steering wheel rotates right about 10 degrees and holds there as the car drifts slowly right. It wont steer all the way, just about 10 degrees and hold there. I don't think that the calipers are sticky or air in the lines because the brakes feel incredible and stop on a dime with great modulation and feel. They also release cleanly. My hunch: -Wheel alignment off due to a worn bushing causing the wheels to shift under braking. -Uneven length T/C rods. (I have a 1/8" or so washer on one, behind the front bushing, to make it longer so that the left and right wheelbases match). -Worn REAR OUTER spindle-pin bushings. (the ONLY original bushings still in my Z). Everything else is Poly or aluminum/delrin. The car has no crash history that I know of, or can see. The ride heights are even all around. Quote Link to comment Share on other sites More sharing options...
2126 Posted May 28, 2008 Share Posted May 28, 2008 Just a hunch but, it may be a simple difference in tire pressures....right & left! Tom Quote Link to comment Share on other sites More sharing options...
HoustonZ Posted May 28, 2008 Share Posted May 28, 2008 Mine does the same thing. I think my problem might be that one disc is a little thicker then the other. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 28, 2008 Share Posted May 28, 2008 Caster being off on one side vs the other will cause more of a pull than the TC rods being different lengths. Quote Link to comment Share on other sites More sharing options...
buZy Posted May 28, 2008 Share Posted May 28, 2008 Same brakes here but stops straight. Could it be the natural convex shape in the road? Higher in the center lower towards each end to shead rain water typical. Winter driving is a prime example of this pulling the car into the ditch under threshold braking. Have you tried it in a true flat and level parking lot? I have noticed with too much rear brake bias input the car will get a bit "loose" under braking and not stop as straight. You may want to try more front bias and see if it has any effect. Or like you say the rear spindle bushings may be having a similar situation. Tire pressures as well. If your alignment is off, any difference in tire wear left to right? Quote Link to comment Share on other sites More sharing options...
wrxand280z Posted May 29, 2008 Share Posted May 29, 2008 Have you replaced your brake lines? If not you may have a colasped one which would mean you not be getting enough pressure and thus one wheel would brake while the other does not. Quote Link to comment Share on other sites More sharing options...
benitoz Posted May 29, 2008 Share Posted May 29, 2008 I agree with buzzy the slant of the road will do that try it in a parking lot that really flat Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 29, 2008 Author Share Posted May 29, 2008 I agree with buzzy the slant of the road will do that try it in a parking lot that really flat My brake lines are new with the brake kit. I also thought it might be the crown on the road so I tried straddling the double yellow to get as neutral of a surface as I could. It pulls the same. Tire pressures are even all around. buZy, The brake bias test is a great idea. If I go more rear bias and it gets worse, I know the problem could likely be from the rear wheels or vice versa. I will double check my alignments, toe, caster, camber to make sure they are right on. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 29, 2008 Share Posted May 29, 2008 What kind of TC rod bushings are you using? They flex when you hit the brakes, changing the caster under load. I'd suspect a bad TC rod bushing or a stuck piston in a caliper on the right. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 29, 2008 Author Share Posted May 29, 2008 This is not a new problem, the car has had this tendency for as long as I can remember but is more pronounced with loads generated by the AZC brakes. The TC bushings are Poly in front of the bucket, and factory rubber on the back of the bucket. When I measured wheelbase on my Z a couple of years ago I noticed that the left front wheelbase was 1/4" shorter than the right. The left front wheel was also 1/4" further back in the wheel well arch compared to the right front wheel. I put a 1/8" or so washer behind the left poly TC bushing to push the left front forward. This made the wheelbase match left and right. I did check caster with a bar, spirit level, strings and a tape measure. It appeared to be pretty even with my crude measurment system. (geometry is my forte) Maybe it's time to get on a REAL alignment machine and get a readout of all the angles. I will also check the calipers for free motion. I doubt it's the calipers but sometimes it's the simplest thing. The ONLY thing I have never changed are the spindle pin bushings. They always appeared to be in good enough condition and I can't detect any flex or odd toe in the rear. I can't gaurantee that the spindle pin bushings are not flexing under brake loads, though the car is dead stable and straight, on the highway and hard accel. My tire wear has always been nearly even all around. Quote Link to comment Share on other sites More sharing options...
buZy Posted May 29, 2008 Share Posted May 29, 2008 If possible check the free running (no braking heat input) rotor temps with one of those lazer temp guns. Having one of those tools is really useful! Quote Link to comment Share on other sites More sharing options...
johnc Posted May 29, 2008 Share Posted May 29, 2008 The wheelbase on the 240Z is supposed to be different left to right. Try taking out the 1/8" spacer. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted May 29, 2008 Share Posted May 29, 2008 Do you have bump steer spacers? On mine it started doing this, one of them had gotten slightly loose, and I guess it would only move slightly under heavy braking. Mario Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted May 29, 2008 Share Posted May 29, 2008 The wheelbase on the 240Z is supposed to be different left to right. Try taking out the 1/8" spacer. Seriously? What would be the motive behind this? Quote Link to comment Share on other sites More sharing options...
m4xwellmurd3r Posted May 29, 2008 Share Posted May 29, 2008 I'm not sure but it might be to counter having the driver in the car. Someone was having some alignment issues with their Z, and the alignment left to right is completely different all around (not symetrical at all) and that's normal. actually the only thing wrong with his was his left rear (i think) was a bit toed for one reason or another. I thought it was really weird that the alignment was so different between left and right. so by making that left side longer it could make it shift to the right I suppose. I'd go with taking out that spacer and see what happens. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 30, 2008 Author Share Posted May 30, 2008 Wow, I didn't know that about the left to right wheelbase being off. I wonder if it's because they use only one rear control arm design flipped over left to right? Taking the spacer out would be fairly easy to try first. Quote Link to comment Share on other sites More sharing options...
Careless Posted May 30, 2008 Share Posted May 30, 2008 Seriously? What would be the motive behind this? mounting of the steering rack, I think. I know, newer cars are equal on both sides in most cases but i do believe the steering rack is offset on one side due to where the shaft falls (jdm or usdm). just a hunch. :-/ EDIT: oh wait, "wheelbase"? what the flux core? Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted May 30, 2008 Share Posted May 30, 2008 Wasn't the engine offset 3/4" right, maybe that has to do with it. I am perplexed. JohnC is just waiting for all the fish to nibble on this one! Hmmm. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 30, 2008 Share Posted May 30, 2008 Road crown. Quote Link to comment Share on other sites More sharing options...
woldson Posted May 30, 2008 Share Posted May 30, 2008 Ahhh crud you beat me too it^^........ Quote Link to comment Share on other sites More sharing options...
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